Dual-clutch assembly

ABSTRACT

A dual clutch assembly includes a torsional vibration damper and a dual clutch. The vibration damper has a primary side which can be coupled to a driving member for joint rotation about an axis, a secondary side which is rotatable about the axis, and a damper element arrangement between the primary side and the secondary side. The dual clutch includes an input area and two output areas, the input area supporting the secondary side of the torsional vibration damper in at least one of an axial and radial direction with respect to the primary side, each output area being coupleable with a respective driven member so as to be fixed against rotation with respect to the driven member. A bearing arrangement supports the input area in at least one of an axial and a radial direction with respect to a stationary subassembly.

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/EP2003/012869,filed on 18 Nov. 2003. Priority under 35 U.S.C. §119(a) and 35 U.S.C.§365(b) is claimed from German Application No. 102 54 900.1, filed 22Nov. 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to a dual-clutch arrangementcomprising a torsional vibration damper arrangement with a primary sidewhich can be fixedly coupled with a driving member for joint rotationabout an axis of rotation and a secondary side which is rotatable aboutthe axis of rotation against the action of a damper element arrangementwith respect to the primary side, and a dual clutch with an input areaand two output areas, each of the output areas being coupleable with oneof two driven members so as to be fixed with respect to rotationrelative thereto.

2. Description of Related Art

U.S. Patent No. 6,634,477 discloses a dual clutch arrangement in whichthe primary side of a torsional vibration damper arrangement is fixedlycoupled with a drive shaft as driving member by means of screw bolts.The secondary side of the torsional vibration damper arrangement issecurely supported by a bearing support at the primary side in axial andradial direction and is rotatable with respect to the latter. The inputarea of the dual clutch is coupled substantially rigidly with thesecondary side of the torsional vibration damper arrangement. In thiscase, these two subassemblies are only movable axially with respect toone another and the input area of the dual clutch is biased orpretensioned in the direction of the torsional vibration damperarrangement by a pretensioning spring that is supported with respect toa transmission housing.

A substantial problem in systems of this kind serving to transmit torquebetween a drive unit and a transmission is that there is a mechanicalredundancy particularly in the engaged state of one of the couplingareas of the dual clutch. This means that if different subassemblieshave an axial offset or an axial inclination with respect to oneanother, the redundancy leads to constraints or loads which putconsiderable stress on the existing bearing supports or supportingareas.

It is the object of the present invention to provide a dual clutcharrangement in which movement irregularities caused by a shaft offset orshaft tilt cannot lead to an overloading of the bearing areas.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, this object is metby a dual clutch arrangement comprising a torsional vibration damperarrangement with a primary side which can be fixedly coupled with adriving member for joint rotation about an axis of rotation and asecondary side which is rotatable about the axis of rotation against theaction of a damper element arrangement with respect to the primary side,and a dual clutch with an input area and two output areas, each of theoutput areas being coupleable with one of two driven members so as to befixed with respect to rotation relative thereto, wherein the secondaryside of the torsional vibration damper arrangement is supported withrespect to the primary side of the torsional vibration damperarrangement in axial direction and/or in radial direction by the inputarea of the dual clutch and a bearing arrangement which supports thisinput area with respect to a stationary subassembly.

Accordingly, substantially only one area of the bearing or support isprovided, namely, with respect to a stationary subassembly. In thetorsional vibration damper arrangement itself, the primary side andsecondary side interact with one another substantially only by way ofthe damper element arrangement, possibly a friction device or the like.However, there is no bearing arrangement for axial or radial support inthe torsional vibration damper arrangement itself.

In this connection, it can advantageously be provided that thestationary subassembly can preferably comprise a transmission housing.

According to another aspect of the present invention, the above-statedobject is met by a dual clutch arrangement comprising a torsionalvibration damper arrangement with a primary side which can be fixedlycoupled with a driving member for joint rotation about an axis ofrotation and a secondary side which is rotatable about the axis ofrotation against the action of a damper element arrangement with respectto the primary side, and a dual clutch with an input area and two outputareas, each of the output areas being coupleable with one of two drivenmembers so as to be fixed with respect to rotation relative thereto,wherein the input area of the dual clutch is supported with respect tothe secondary side of the torsional vibration damper arrangement one theone hand and with respect to a stationary subassembly on the other handby a flexible coupling arrangement.

Since the input area of the dual clutch in this arrangement is coupledwith the torsional vibration damper arrangement as well as with astationary subassembly, which can also be constructed again as atransmission housing, by incorporating flexibility, the input area ofthe dual clutch can carry out compensating movements without leading toconstraints and, therefore, overloading in the area of the systemcomponents serving as bearing support.

The flexible coupling arrangements preferably permit a movement of theinput area of the dual clutch in radial direction and/or in axialdirection. In order to provide for a defined support particularly in thetorsional vibration damper arrangement, it is suggested that thesecondary side of the torsional vibration damper arrangement issupported by an axial bearing and a radial bearing at the primary sideof the torsional vibration damper arrangement.

According to another aspect of the present invention, a dual clutcharrangement is suggested which comprises a torsional vibration damperarrangement with a primary side which can be fixedly coupled with adriving member for joint rotation about an axis of rotation and asecondary side which is rotatable about the axis of rotation against theaction of a damper element arrangement with respect to the primary side,and a dual clutch with an input area and two output areas, each of theoutput areas being coupleable with one of two driven members so as to befixed with respect to rotation relative thereto, wherein the secondaryside of the torsional vibration damper arrangement is supported withrespect to the primary side of the torsional vibration damperarrangement by an axial/radial bearing arrangement which permits tiltingof the secondary side with respect to the primary side.

In particular, when it is further provided that the secondary side ofthe torsional vibration damper arrangement is coupled with the inputarea of the dual clutch by a coupling arrangement so as to be fixed withrespect to rotation relative to it, which coupling arrangement permits atilting of the secondary side with respect to the input area, thesecondary side can act as a compensating member which can compensate apossible axial offset between the primary side, for example, a driveshaft, and the input area of the dual clutch, for example, a drivenshaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view in partial longitudinal section showing a dual clutcharrangement according to the invention;

FIG. 2 is a view corresponding to FIG. 1 of a modified embodiment form;

FIG. 3 is a view corresponding to FIG. 1 of a modified embodiment form;

FIG. 4 is a view corresponding to FIG. 1 of a modified embodiment form.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

In FIG. 1, a dual clutch arrangement 10 comprises two system areas,namely, a torsional vibration damper arrangement 12, constructed as adual mass flywheel, and a dual clutch 14.

The torsional vibration damper arrangement 12 has a primary side 16which substantially comprises a primary mass 18 and a central diskelement 22 which is fixedly connected to the latter by screw bolts 20.The primary side 16 is coupled by means of the screw bolts 20 with adriving member, e.g., a crankshaft of an internal combustion engine, soas to be fixed with respect to rotation relative to it.

The torsional vibration damper arrangement 12 further comprises asecondary side 24. This secondary side 24 is substantially formed of twocover disk elements 26, 28 which are formed, for example, by deformationof sheet-metal parts. These two cover disk elements 26, 28 lie on bothsides of the central disk element 22 in their radial inner area. Theyare fixedly connected on the radial outer side, e.g., by screwing,riveting, welding, or the like.

Spring windows 30, 32, 34 are provided in the two cover disk elements26, 28 and the central disk element 22 at a plurality of circumferentialpositions. The spring windows 30, 32, 34 have circumferentialextensions—with respect to an axis of rotation A—which correspond to oneanother and serve to receive, respectively, damper springs 36 which, intheir entirety, form a damper element arrangement 37. In thecircumferential direction, these damper springs 36 are received in thespring windows 30, 32, 34 so as to be compressed. The cover diskelements 26, 28 are rotatable with respect to the central disk element32 by compression of these springs 36, so that the primary side 16 inprinciple is also rotatable about the axis of rotation A with respect tothe secondary side 24. To dissipate vibration energy during thisrelative rotation, which can also occur in the event of excessive torquevariation, a permanently-acting or delayed-action friction device 38 ofknown construction can act between the primary side 16 and the secondaryside 24.

The dual clutch 14 substantially comprises two coupling areas 40, 42.The first coupling area 40 has a pressing plate 44 which is coupled withan abutment plate 46 so as to be fixed with respect to rotation butaxially movable relative thereto by tangential leaf springs or the like,this abutment plate 46 having the shape of an annular disk. An actuatingforce transmission arrangement 48 of the first coupling area 40comprises two force transmission parts 50, 52 which are constructed, forexample, in a cup-shaped manner and which span the abutment plate 46axially. The force transmission element 50 is supported at the pressingplate 44, e.g., by means of a wear compensating device. The forcetransmission element 52 is acted upon by a force exerting arrangement 54which is supported, in turn, at a base area 56 of a housing arrangement58 that is fixedly connected to the abutment plate 46. An actuatormechanism 60 acts upon the radial inner area of the force exertingarrangement 54. This actuator mechanism 60 is only shown schematicallyand is substantially represented by a rotation decoupling bearing whichis displaceable axially along a supporting element 52 for carrying outengagement processes in order to displace the radial inner area of theforce exerting arrangement 54 in direction of the torsional vibrationdamper arrangement 12 and, in so doing, to displace the actuation forcetransmission arrangement 48 in the opposite direction and to displacethe pressing plate 44 in the direction of the abutment plate 46. In thisway, the friction linings 64 of a clutch disk 66 are clamped in andtransmit a torque via this first coupling area 40 to a transmissioninput shaft that can be coupled to the clutch disk so as to be fixedwith respect to rotation relative to it.

The second coupling area 42 likewise has a pressing plate 68 that iscoupled with the abutment plate 46 and the housing 58, respectively,e.g., again by tangential leaf springs or the like, so as to be fixedwith respect to rotation relative thereto, but is displaceable indirection of the axis of rotation A with resect to this subassembly. Aforce exerting arrangement 70 of the second coupling area 42 issupported on the radial outer side at the base area 56 of the housing 58and can act upon the pressing plate 68 further inward radially. Anactuator mechanism 72 acts on the radial inner end of this forceexerting arrangement 70, so that this bearing can be displaced againalong the supporting element 62 or in axial direction with respect tothe latter during the movement of the mechanism, also substantiallyrepresented by a rotation decoupling bearing, and, by means of themovement of the force exerting arrangement 70 in the direction of thepressing plate 68, can move this pressing plate 68 in the direction ofthe abutment plate 46. In so doing, the friction linings 74 of a clutchdisk 76 are clamped between the pressing plate 68 and the abutment plate42 so that a torque can be transmitted to a second transmission inputshaft in this engaged state of the second coupling area 42 by means ofthis coupling area 42, which second transmission input shaft ispositioned coaxial to the first transmission input shaft alreadymentioned. The two clutch disks 66, 76 form respective output areas ofthe coupling areas 40, 42.

With respect to the two actuator mechanisms 60, 72, it is noted thathydraulic, pneumatic or mechanical systems can be used to generate theiraxial movement and that of their rotation decoupling bearing. Further,it is possible that the supporting element 62, which is fastened to atransmission housing 80 or the like by a carrier element 78, is providedwith a thread at an inner circumferential side and an outercircumferential side, respectively, and elements 82, 84 that arerotatably supported on the supporting element 62 are provided withcomplementary threads so that a rotation of these elements 82, 84 alsosimultaneously results in their axial displacement and in the executionof engaging or disengaging processes.

The dual clutch 10 described above, like the torsional vibration damper12 described above, can be constructed differently in different areas.For example, instead of the normally-open construction described above,in which an engagement force must be generated in the respectiveactuator mechanism 60, 72, the dual clutch can be constructed as anormally-closed system when using force accumulators in at least one ofthe coupling areas 40, 42.

It will be seen in the construction shown in FIG. 1 that there is noaxial or radial bearing arrangement between the primary side 16 and thesecondary side 24 in the area of the torsional vibration damperarrangement 12. A support with respect to force is provided in this casesolely by the damper element arrangement 37 and the respective springs36 thereof Due to the fact that there is generally a gap between thecover disk elements 26, 28 and the central disk element 22, a certainfreedom of movement exists between the primary side and the secondaryside 24 which is not limited by any bearing supports. The bearingsupport of the secondary side 24 is carried out in that the latter isfixedly connected by screw bolts 86 to the abutment plate 46 and,therefore, also to the housing 58 by means of the cover disk element 28.However, the housing 58 is supported axially and radially at thesupporting element 62 by another rotation decoupling bearing 88, andthis supporting element 62 is supported in turn in a stationary mannerwith respect to the transmission housing 80. Accordingly, the secondaryside 24 is substantially fixedly connected to the input area 90 of thedual clutch 10, which input area 90 is in turn fixedly supported axiallyand radially with respect to the transmission housing 80, but also so asto be rotatable with respect to the latter. It should also be noted thatthe input area 90 of the dual clutch 10 substantially includes theabutment plate 46, the housing 58 and the components, particularly thepressing plates 44, 68, that are coupled therewith so as to be fixedwith respect to rotation relative to them. Also, various systemcomponents used for actuation, such as the actuation force transmissionarrangement 48, can be included in this input area 90.

This construction makes it possible to compensate for an axial offset oraxial inclination between the drive shaft and the driven shafts becauserelative movements between the primary side 16 and secondary side 24 canoccur in both radial and axial direction, particularly in the area ofthe torsional vibration damper arrangement 12. Wobbling movements canalso be carried out in this area.

The assembly of this dual clutch arrangement 10 is carried out in such away that the torsional vibration damper arrangement 12 is initiallyconnected to the drive unit on the radial inner side by the screw bolts20. Subsequently, the dual clutch 14 which has already been joined to atransmission is fitted axially and the screw connection can then beproduced by means of the screw bolts 86. Accordingly, this screwconnection functions as both rotational coupling and axial fastening. Itis also possible, for example, to realize the rotational couplingfunction in another manner by means of toothing arrangements, rotationalcoupling pins or the like, while screw bolts or the like are used forfixing axially.

FIG. 2 shows an embodiment form of a dual clutch arrangement accordingto the invention in which components corresponding with respect toconstruction or function to the components described above aredesignated by the same reference numbers with the addition of an “a”.The basic construction corresponds to that described in the precedingand only the difference between the two will be described.

First, it will be seen in the area of the torsional vibration damper 12a that the two cover disk elements 26 a, 28 a now substantially form theprimary side 16 a, while the central disk element 22 a, together with amass part 92 a, substantially forms the secondary side, these two partsbeing fixedly connected to one another by rivet bolts 94 a. The centraldisk element 22 a is supported axially with respect to the primary side16 a by an axial bearing ring 95 a. A radial bearing support of thecover disk element 26 a and central disk element 22 a with respect toone another is provided by means of a radial bearing element 96 a thatis positioned between respective axially extending cylindrical portionsof the cover disk element 26 a and central disk element 22 a.

The dual clutch 14, whose construction substantially corresponds to theconstruction described above, is coupled in the input area 90 a, in thiscase in the area of the abutment plate 46 a, with the mass part 92 a ofthe secondary side 24 a. For this purpose, a flexibly acting couplingarrangement 98 a is provided. This can comprise, for example, at theabutment plate 46 a, a plurality of coupling pins 100 a which engage inelastomer material 102 a which is provided at the mass part 92 a andpartially embedded therein. In this way, the input area 90 a of the dualclutch 14 a is flexibly coupled with the secondary side 24 a of thetorsional vibration damper arrangement 12 a.

The coupling and support of the input area 90 a of the dual clutch 14 awith respect to a stationary system area, that is, for example, withrespect to the transmission housing 80 a, is also carried out by meansof a flexibly acting coupling arrangement 104 a. The latter can againcomprise, for example, at the carrier element 78 a already mentioned,coupling pins 106 a which engage in elastomer material 108 a. Thiselastomer material 108 a is carried by the transmission housing 80 a andis partially embedded therein. Accordingly, the dual clutch 14 a is alsoflexibly supported at the other axial area by its input area 90 a bymeans of the housing 58 a, the rotation decoupling bearing 88 a and thesupporting element 62 a. Therefore, in spite of any redundancy existingwith respect to the quantity of fixing points or fastening points due tothe elasticity introduced in the area where the dual clutch 14 a iscoupled on both sides, it is ensured that compensating movements cantake place so that axial offsetting or relative axial inclinations canbe compensated.

The dual clutch 14 a is again initially fastened to the transmission inthis arrangement, while the torsional vibration damper arrangement 12 ais fastened to the drive unit. These two system areas are then movedtogether axially so that the pins 100 a are inserted into the elastomermaterial 102 a. In this way, the pins 100 a with the elastomer material102 a simultaneously also function as a rotational coupling. Anyelastomer material that can absorb corresponding loads, e.g., natural orsynthetic rubber material, may be used. Metal bushings around which theelastomer material is molded can advantageously be provided at aplurality of circumferential positions.

Another embodiment form of a dual clutch arrangement according to theinvention is shown in FIG. 3. Components which correspond with respectto construction or function to the components described above aredesignated by the same reference numbers with the addition of a “b”.Again, only differences in construction will be described in thefollowing.

In the variant of the dual clutch arrangement 10 b shown in FIG. 3, inwhich the construction of the torsional vibration damper arrangement 12b corresponds substantially to the variant described with reference toFIG. 1, the secondary side 24 b of the torsional vibration damperarrangement 12 b is supported with respect to the primary side 16 b,namely, with respect to a cylindrical shoulder 112 b located on theradial inner side of the mass part 18 b, by a bearing arrangement whichsubstantially comprises a bearing ring 110 b. This cylindrical shoulder112 b has a spherical or convex end face 114 b at its axial end. Thebearing ring 100 b has a concave annular surface 116 b which correspondsto this spherical or convex end face 114 b and which rests at thesurface 114 b of the mass part 18 b. The cover disk element 28 b of thesecondary side 24 b is supported in its radial inner area on the bearingring 110 b. A wobble decoupling between the primary side 16 b and thesecondary side 24 b is also provided in this case because of thepractical movability—already mentioned with reference to FIG. 1—of thetwo cover disk elements 26 b, 28 b with respect to the central diskelement 22 b, which is substantially not impeded by the bearing ring 100b and its movability on the convex surface 114 b. Slight relative axialmovements of these two subassemblies with respect to one another canalso take place.

The dual clutch 14 b is held by its input area 90 b by the supportingelement 62 b and the carrier element 78 b with respect to a stationarysubassembly, that is, for example, the transmission housing 80 b. Inthis case, coupling pins 118 b can be used like the screw bolts shown inFIG. 1. In this way, a defined support of the input area 90 b, that is,substantially also the housing 58 b and the abutment plate 46 b, isrealized. In order to allow for the aforementioned wobbling movement ofthe secondary side 42 b with respect to the primary side 16 b, arotational driving coupling permitting a decoupling of this kind isprovided between the cover disk element 28 b and the abutment plate 46b. For this purpose, rotational coupling pins 120 b which engage inassociated openings of a radial flange 122 b of the cover disk element28 b are provided, e.g., at the abutment plate 46 b. A disk spring 124 bwhich provides an axial pretensioning for the secondary side 24 b can beassociated with each of these pins 120 b so as to provide stationarycontact between the two surfaces 114 b, 116 b. In order to realize thewobbling decoupling mentioned above, it is advantageous to provide an atleast slight movement play permitting tilting in the area where the pins120 b fit into the associated openings of the cover disk element 28 b.Of course, other flexible coupling arrangements, e.g., the couplingarrangement shown in FIG. 2, or a decoupling by tangential leaf springsor the like can also be realized. It is also possible, of course, to useother pretensioning elements such as spring rings or the like.

The assembly of this embodiment form is carried out in that thetorsional vibration damper arrangement 12 b is again first screwed ontothe drive shaft. The dual clutch 14 b which is already joined to thetransmission is then advanced axially and the coupling with the coverdisk element 28 b is realized in the area of the pins 120 b. This can becarried out in such a way that the pins 120 b are not inserted intoassociated openings until after the dual clutch 14 b is advancedaxially.

FIG. 4 shows a modification of the embodiment form shown in FIG. 3. Inthis case, the secondary side 24 b comprises two ring disk elements 130b and 132 b which are nested one inside the other coaxially. The ringdisk element 130 b is fixedly connected to the cover disk element 28 b,for example, by riveting, while the radial outer ring disk element 132 bis fixedly connected to the input area 90 b of the dual clutch 14 b byscrewing. These two ring disk elements 130 b, 132 b are decoupled fromone another in an engagement area 134 b in which the two ring diskelements 130 b, 132 b adjoin one another, for example, by forming teethand possibly with the intermediary of flexible materials, in such a waythat a rotational driving function is realized in practice by a positiveengagement, but the inner ring disk element 130 b is otherwise at leastslightly tiltable with respect to the outer ring disk element 132 b.

Also provided in this embodiment form is a bearing ring 100 b at whichthe inner ring disk element 130 b of the secondary side 24 is nowsupported on the one hand and which is supported again with a convexsurface 116 b at a correspondingly concave surface 114 b of the primaryside 16 b, namely, at a supporting element 138 b which is coupled withthe central disk element 22 b by the screw bolts 20 b. In this way, theinner ring disk element 130 b, together with the two cover disk elements26 b, 28 b, is again tiltable with respect to the primary side 16 b.

The input area 90 b of the dual clutch 14 b is supported in the area ofits housing 58 b by the rotation decoupling bearing 88 b and thesupporting element 62 b, mentioned above, with respect to thetransmission housing 80 b. In this case, a pretensioning spring 140 bensures that the entire input area 90 b is pretensioned in the directionof the torsional vibration damper arrangement 12 b. An axial movementstop is provided in the area of the coupling of the two ring diskelements 130 b. The pretensioning spring 140 b ensures that the bearingring 100 b remains in firm bearing contact with the surface 114 b at thesupporting element 138 b. This system is again constructed in such a waythat the torsional vibration damper arrangement 12 b is initiallyfastened to the drive element. The dual clutch 14 b which is alreadyjoined to the transmission is then fitted and the outer ring diskelement 132 b is already fixedly connected to the abutment plate 46 band, as is shown in FIG. 4, itself forms an abutment plate for the firstcoupling area 40 b. The two ring disk elements 130 b, 132 b then enterinto a coupling interaction in their coupling area 134 b while retainingthe wobbling movability of the secondary side 24 b, mentioned above, toa limited extent.

The invention provides various possibilities for coupling differentsystem areas of a dual clutch arrangement which either avoid redundancyin fastening and, therefore, also permit compensating movements in theevent of axial offset or axial relative tilting or which permit acertain relative movement in case of redundancy due to a flexibleconnection of different system areas.

1. A dual clutch assembly comprising: a torsional vibration dampercomprising a primary side which can be coupled to a driving member forjoint rotation about an axis, a secondary side which is rotatable aboutthe axis, and a damper element arrangement between the primary side andthe secondary side; a dual clutch comprising an input area and twooutput areas, each said output area being coupleable with a respectivedriven member so as to be fixed against rotation with respect to saiddriven member; an axial/radial bearing arrangement which supports thesecondary side of the torsional vibration damper arrangement withrespect to the primary side so that the secondary side can tilt withrespect to the primary side; and a coupling arrangement which fixes theinput area of the dual clutch against rotation with respect to thesecondary side of the torsional vibration damper arrangement, saidcoupling arrangement permitting the secondary side to tilt with respectto the input area.